Tabulation gap persists

The purpose of tabulation is to align the text after the TAB character to
a particular position (see the first line in this picture):

When placing more text to the left of the TAB character the gap closes more and more and eventually disappears, because the TAB character looses its function as soon as the previous character ends beyond the tab-position (10 cm in the picture).

Error in FrameMaker 7.0 and 7.1

In FrameMaker 7.0 and 7.1 however, the gap does not close completely. This situation can even be printed!